1. Technical Field of the Invention
The present invention generally relates to an alphanumeric data input device. More particularly, the present invention relates to a programmable, one-handed keyboard for use with a computer or other data processing device.
2. Background
Keyboards are the most widely utilized data input device, and are typically configured for two-handed input. The keys on most keyboards are arranged according to the ubiquitous QWERTY layout, where the fingers of the typist rest on the home row keys. More specifically, the left hand rests on the letters A, S, D and F, and operates the keys on the left side of the keyboard, while the right hand rests on the letters J, K, and L, and operates the keys on the right side of the keyboard. All of the characters in the alphabet correspond to a key, and above the uppermost row of alphabetic keys is a row of numeric keys. In addition to the basic alphanumeric keys, a QWERTY keyboard includes one or more shift keys, a space key, an enter key, a tab key, control key, alternate key, and so forth, the functions thereof being well known in the art.
Conventionally keyboards are utilized to input data into text-based applications such as word processors, databases, and the like. For number-rich applications such as spreadsheets, keyboards typically include numeric keypads that are segregated from the standard alphanumeric keys. In such applications, there is no need to simultaneously control alternate input devices such as a mouse since the majority of tasks can be accomplished with standard keystrokes, shortcut keys, and the like. Where the mouse needs to be utilized in order to interact with certain graphics of such applications, one hand may be removed from the keyboard without much reduction in productivity by rapidly returning that hand to the keyboard when necessary to input text data. In other applications, it may be necessary to input data using one hand for extended periods of time while using the other hand for other purposes. For example, in CAD/CAM applications, it is necessary to manipulate the various graphical elements using a mouse, pen input device, or the like while entering dimensions, explanatory captions, and so forth. In another example, inventory recording applications may require the user to handle products while entering details thereof into a database. Therefore, there is a need in the art for one-handed keyboards for the above-described applications.
Another factor driving the need for one-handed keyboards is the increased miniaturization of portable data processing devices such as Personal Digital Assistants (PDAs), smart cellular phones having PDA-like features, laptop computers, and so forth. In this regard, there is a need for keyboards that have a commensurately smaller footprint. The trend has been to reduce the size of the individual keys while still maintaining the QWERTY layout. With substantial decreases in size, only thumb or index finger keying is possible, largely negating the benefits of preserving the layout. Familiarity with the position of each of the keys, however, retains some input efficiency. The cramped layout also increases stress on the fingers, leading to more acute repetitive stress injuries.
One type of one-handed keyboard is a “chording” keyboard. Exploiting the general principle of musical instruments such as pianos, simultaneous striking of various keys results in a distinct alphanumeric character being generated. Because of the finite number of characters that need to be generated, these keyboards have a small number of keys, typically five. The character “A” may be generated by striking the first key, while the character “Z” may be generated by striking all five keys. The complexity of the key sequences and the inefficiency of having to use more than one finger per character have hindered its widespread adoption.
Another approach to one-handed keyboard involves reducing the total number of physical keys, while assigning multiple values to the remaining keys. U.S. Pat. No. 5,288,158 to Matias proposes a one-handed keyboard comprising keys representing one half of a standard keyboard, and the same keys also representing the symmetrically opposite keys of a standard keyboard that are activated with a modifier key. As will be appreciated, the speed, pace, and rhythm of typing relies in part on alternating keystrokes, as it is faster to hit a first key and a second key with different fingers rather than hitting the same keys or different keys with the same finger. Although the Matias device retained the familiar QWERTY layout, there is a higher likelihood of any given keystroke requiring redundant, as opposed to alternating, keystrokes. Accordingly, there is a resulting loss in typing speed and data entry efficiency.
In another approach as proposed by U.S. Pat. No. 6,348,878 to Tsubai, a keyboard layout has fifteen keys, each having a primary letter and a secondary letter. The primary letter is keyed by solely striking the key, while the secondary letter requires striking a modifier key first or simultaneously with the key. Tsubai proposes a layout which minimizes finger travel and keystrokes to generate the most common letters and diagraphs in the English language. While largely eliminating the need to memorize complex chords and reducing instances of redundant keystrokes, typing efficiency is still reduced as compared to full keyboards because modifier keys must be utilized.
Accordingly, there is a need in the art for an improved one-handed keyboard which does not require the user to memorize complex chords or inefficiently fragment keystrokes with modifier keystrokes. There is also a need for a one-handed keyboard having full-sized keys and other ergonomic features while retaining a small footprint.